Hygiea

Hygiea, designated 10 Hygiea, is a large main-belt asteroid. It is the fourth-largest asteroid by diameter and was discovered in 1849 by Italian astronomer Annibale de Gasparis. The name honors Hygieia, the Greek goddess of health, daughter of Asclepius.

Hygiea resides in the outer region of the main asteroid belt. It orbits the Sun with a semi-major axis of about 3.14 astronomical units, an orbital period of roughly 5.6 years, and an eccentricity near 0.11. Its orbit has a modest inclination of a few degrees relative to the ecliptic.

The asteroid measures about 430 kilometers across, making it one of the largest bodies in the belt. It has a low albedo, around 0.06 to 0.08, reflecting its dark, carbon-rich surface. Hygiea is classified as a carbonaceous (C-type) asteroid, indicating primitive materials that may include hydrated minerals and volatiles.

Hygiea is notable for its relatively spherical shape, which is unusual for an object of its size. Some studies have suggested it may be in hydrostatic equilibrium, a state that would make it a candidate for dwarf-planet status, although this interpretation is not universally accepted.

Observations from ground-based telescopes and space-borne infrared instruments have helped constrain its size, shape, and surface properties. Hygiea remains a key object of study for understanding the composition and evolution of large, primitive bodies in the main belt.